How Trauma Affects the Brain — and How Therapy Can Help
Our brains are constantly working behind the scenes—processing sensory experiences, assessing potential threats, and storing memories. When everything is functioning well, these systems work together to help us feel safe, regulate emotions, and make sense of our experiences.
But when trauma enters the picture, it can disrupt this delicate balance. Suddenly, everyday life can feel overwhelming, emotions can become unpredictable, and the past can feel eerily present. If you’ve ever wondered why trauma has such a profound impact on the brain, let’s break it down in a simple way by looking at three key players in the brain’s response system:
The Amygdala: Your Overactive Alarm System
The Hippocampus: The Librarian That Struggles to File Memories
The Prefrontal Cortex: The Wise Leader Who Gets Overwhelmed
Understanding how these parts of the brain function—and how they change in response to trauma—can help us make sense of emotional reactions, triggers, and stress. More importantly, it highlights why therapy can be so effective in helping the brain heal.
The Amygdala: Your Overactive Alarm System
Think of the amygdala as the brain’s alarm system, always scanning for danger. Its job is to detect threats and, if necessary, sound the alarm by releasing stress hormones like adrenaline and cortisol. This helps prepare the body for survival—whether that means fighting, fleeing, freezing, or fawning (pleasing to avoid conflict).
But when someone experiences trauma, the amygdala can become hypersensitive—like a smoke detector that goes off at the slightest hint of toast burning. Even in safe environments, trauma survivors might feel constantly on edge, experiencing intense emotional reactions to things that remind them of past dangers. A loud noise, a certain smell, or a particular place can all trigger the alarm, even when there’s no actual threat.
The Hippocampus: The Librarian Struggling to File Memories
If the amygdala is the alarm system, the hippocampus is like the brain’s librarian. Its job is to organise and store memories properly, ensuring we can tell the difference between past and present events.
In a well-functioning brain, when the amygdala sounds the alarm, the hippocampus checks the archives. It looks for past experiences and determines whether the current situation is actually dangerous. If it finds that the alarm is unnecessary, it tells the amygdala to calm down.
However, trauma can impair the hippocampus, making it harder for it to do its job. Instead of neatly filing a traumatic memory away as something that happened in the past, the hippocampus leaves the memory scattered and disorganised. This is why people who have experienced trauma may struggle with:
Flashbacks or intrusive thoughts – The brain misfiles traumatic events, making them feel as if they are happening right now.
Fragmented memories – Some parts of the trauma are vivid, while other details seem lost or out of order.
Triggers that evoke strong emotions – A smell, sound, or sensation can bring back the emotions of the trauma as if it’s happening again.
The Prefrontal Cortex: The Wise Leader Who Gets Overwhelmed
The prefrontal cortex is the rational, decision-making part of the brain—the wise leader that helps us regulate emotions, think logically, and put things into perspective. When it’s functioning well, it keeps the amygdala in check and helps the hippocampus organise memories properly.
But during a traumatic event, the prefrontal cortex often goes offline. The brain’s priority in a crisis is survival, so rational thought takes a backseat. This is why, in the middle of extreme stress, it can feel impossible to think clearly, control emotions, or make logical decisions.
Over time, if trauma remains unresolved, the prefrontal cortex struggles to regain control. This can make it harder to manage emotions, respond calmly to stress, and feel in control of one’s thoughts and behaviours.
The Good News: The Brain Can Heal
Trauma may reshape the brain, but it doesn’t have to stay that way. Thanks to neuroplasticity, the brain’s ability to rewire and adapt, healing is possible. With the right therapeutic support, these brain systems can be retrained to function in a healthier, more balanced way. Therapy plays a crucial role in:
Calming the Amygdala (Alarm System) – Mindfulness, breathing exercises, and grounding techniques can help turn down the volume on the alarm, reducing hypervigilance and anxiety.
Helping the Hippocampus (Librarian) – Trauma-focused therapies, journaling, and guided memory processing can help properly file past experiences where they belong: in the past.
Strengthening the Prefrontal Cortex (Wise Leader) – Cognitive-behavioural therapy (CBT) and other trauma-informed approaches can help restore rational thinking, emotional regulation, and a sense of control.
Moving Forward
If trauma has left your brain’s alarm system, librarian, and wise leader out of sync, know that healing is possible. Therapy provides the tools to help your brain restore balance, regain control, and, most importantly, feel safe again. Understanding how your brain responds to trauma is the first step toward reclaiming your well-being and moving toward post-traumatic growth.
If you’re ready to start this journey, reaching out to a trauma-informed therapist can be a powerful step forward. Your brain has been doing its best to protect you—now it’s time to help it heal.’
Written by Charlie Haddad, Registered Social Worker
